Willoughby smith



W. SMITH.

INSULATED ELECTRIGAL GONDUOTOR.

(No Model.)

Patented May 8, 1883.

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NITED STATES PATENT muon,

WILLOUGHBY SMITH, OF WHARF ROAD, CITY ROAD, GOUNTY OF MIDDLE- SEX, ENGLAND,

INSUL ATED ELECTRICAL CQNDUCTOR.

SPECIFICATION forming part of Letters Patent No. 2773366, dated May 8, 1883.

Application filed March 6, 1882. (Ne model.) Patented in England December 21, 1881, No. 5,599; in Frayce March 14, 1882,

No. 147,&66, and 'n Belgium March 15, 1882, No. 57.363.

To all wlom 'it 'may concern:

Be it known that I, WILLOUGHBY SMITH, a subject of the Queen of Great Britain, residin'g at Wharf Road, City Road, in the County of Middlesex, England, have invented certain new and useful Improvements in Insulated Conductors for Telegraphic and other Uses, (for which a provisional specification has been lodged by me in Great Britain,No. 5,599dat e d 'o December 21,1881;) and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to nake and use the same.

This invention has for its object improvements in insulated conductors for telegraphic and other uses.

The insulated conductors now used in suhmarine, subterranean, and other telegraphs consist for the most part of copper wire covered with gutta-percha, and 'the gutta-percha is used`in as pure a state as it can be obtained.

Now,for this pure material, which is expensive,

1 substitute a compound of gutta-percha with 2 5 zine-white. This substitution may be made to a considerable extent not only for the sake of economy, but also with advantage having rcgard to the purpose for which the conductor is employed. lprefer to admix the gutta-percha 0 with about an equal proportion, by weight, of

Zinc-white. The admixture is made while the gntta-percha is being Inasticated in an ordinary masticating-machine.

The compound may be used alone for covering the metallic wire conductor, and it may be put onto the conductor in any desired number of concentric' layers, just as gutta-percha is now laid onto metallic conductors. Preferably,however,I first 'coat the netallic conductor with one or more concentric layers of guttapercha, and outside these I apply one or more layers of the compound. The great advan tage the compound possesses over gutta-percha is that it is not liable to change and' decay by 5 long exposure to air, but remains unaltered,

whereas gutta-percha deteriorates in quality and perishes. The compound can therefore be used With great advantage for giving an outer covering to metallic cond uctors after they have had one or more coatings of gutta-percha applied to them, as it will not only protect these inner coatings, but will also aid in insulating the wire, for although the insulating property of the compound is not so high as that of pure guttapercha, still its nsulating-power is high t as compared with other compounds used for insulatin g purposes. For long lines especially it is better to give the wire conductors one or more layers of pure gutta-percha before giving them an outer coating of the compound, as the iductive capacity of the compound is high. This, however, is not of importance for short lines.

In the accompanying drawings, Figure l is a viewpartly in longitudinal section; and Fig. 2, a t'ransverse section, designed to show the manner in which a wire, a, is coated with layers b of gutta-percha, in turn coatedwith the covering c of the compound of gutta-percha and zine-white Having thus described the nature of my in- Vention and the' manner ofperforming the same, I would state that I do not make claim to the admixture of Zinc-White with *gutta percha; but

I claim l. The insulated electric conductor consisting of an inner metalhc conductor and an outer covering of a compound of gutta-percha and zine-white, substantiall y as herein described.

2. The insdlated electric cpnductor consisting of an inner metallicconductor covered with guttaperchaor otherinsulating substance, and

an outer covering of a compound of gutta-.

percha and Zinc-white, substantially as described.

WILLOUGHBY SMITEI.

Witnesses:

J NO. DEAN, T. J. OSMAN, Both of No. 1`7 Gmcch'wch Street, London. 

